Mr. Pass I have a question regarding the Gate connections on the input diff pair.

On a number of the more recent Zens and now on the F1 the bias resistors connect directly to the gates rather than to the outside terminal of the 221 ohm damper resistor. I understand that the damper resistor can be omitted if the impedance at the gate node is so low that oscillation isn't possible. A good example of this would be the lower CCS of the F1. However, the impedance on the Gates of the F1 diff pairs is quite high.

Heres my question:

Is there a sonic difference between connecting the bias resistors directly to the Gate as opposed to the outside end of the 221 ohm resistors?

Thank you.

Regards,
Graeme

Nelson Pass

17th February 2006 07:24 PM

It's really unimportant. The requirement is that there be a
minimum resistance before meeting a non-resistive component,
such as a capacitor or some part of a semiconductor. You can
attach arbitrarily high resistance values on the gate side or
the outside of this minimum resistance, and it doesn't make any
difference in a circuit like this.